An epitaxial growth method can grow on a crystal substrate a single crystal having a crystal orientation identical to that of the crystal substrate, and thus is used in various fields.
For example, the following Patent Documents 1 and 2 describe methods for manufacturing a silicon wafer by an epitaxial growth method of Si.
In the above epitaxial growth method, it is preferable that a substrate, on which a film is deposited, is heated to a temperature higher than a decomposition temperature of a source gas so that the source gas can be thermally decomposed. Accordingly, induction heating using a coil may be used to heat the substrate for example.    Patent Document 1: Japanese Patent Laid-open Application No. H9-232275    Patent Document 2: Japanese Patent Laid-open Application No. 2004-323900
However, a source gas may have a high thermal decomposition temperature. In such a case, it is required to increase a temperature of the substrate to be higher than the thermal decomposition temperature, which makes it difficult to use the induction heating for a film deposition apparatus. For example, although the induction heating using a coil provides better temperature uniformity compared to the case of using a heating unit such as a heater or the like, the induction heating using a coil may have difficulty in uniformly heating an object because a higher heating temperature is required if a gas having a high thermal decomposition temperature is employed. In addition, the temperature of the substrate may vary, for example, depending on the flow of the film deposition gas such that it decreases at the upstream gas flow side and increase at the downstream gas flow side. Moreover, in the case of induction heating, a temperature difference may occur between a central portion and a peripheral portion of a substrate supporting unit supporting a substrate.
The above-described deterioration in the temperature uniformity of the substrate leads to non-uniform film deposition. Therefore, the intra- and the inter-substrate variations in film thickness or film quality can be increased, which results in unstable film deposition.